In North America, injection drug users (IDU) are one of the most at-risk groups for Hepatitis C infection. This infection, and the resulting health issues such as liver cirrhosis and cancer, are anticipated to cost the Canadian healthcare system between $133 and $209 million annually in the coming decades. Although previous research has shown that approximately 50% to 90% of IDU may have already contracted the infection, research to date has focused mostly on preventing the transmission of Hepatitis C in this population. In response, this research will explore injection drug users' (IDU) access to diagnostic services, treatment and care for Hepatitis C infection. It will use data from three on-going long-term studies of IDU in Vancouver, Canada to understand what proportion of IDU in these studies have accessed Hepatitis C testing, treatment, and care. The research will also seek to identify particular characteristics, such as age, sex, incarceration, involvement with sex work, or ethnicity, that are associated with increased or decreased access to these services. Similarly, it will identify characteristics related to completion of a full session of Hepatitis C treatment. The data that will be used for this research were gathered through initial baseline and semi-annual follow-up questionnaires, administered by study interviewers to IDU. Participants were asked about topics including socio-demographic information, drug use behaviour, interactions with law enforcement, and sexual activity. The survey also includes standardized tools for the assessment of mental health and depression, and blood samples were collected for diagnostic purposes including the detection of Hepatitis C infection. Statistical analysis of this data will provide an understanding of injection drug users' access to Hepatitis C diagnostics, treatment and care. It will also help identify the barriers and facilitators to these services, highlighting strengths and critical gaps in Hepatitis C-related service provision for this high risk population. Given that analysis will also characterize any differences in access based on age, sex, or Aboriginal ancestry, the proposed research will also provide information on the unique situations and barriers to access experienced by distinct sub-populations of IDU. Overall, this study will help healthcare providers and policy makers to strengthen Hepatitis C diagnostics, treatment and care delivery to IDU, contributing to improved health outcomes for this at-risk population.